Search PubMed⌕ Search

Biomedical subjects

C Kawai

Publications and source records attributed to C Kawai.

At least 217 records · Page 12Linked to original sources
PubMed1989

Combined effect of disopyramide and bethanechol: use of bethanechol to prevent anticholinergic side effects of disopyramide without reduction of antiarrhythmic efficacy.

Because bethanechol chloride (B) relieves the anticholinergic side effects of disopyramide (D), we examined the combined effects of D and B on the heart and urinary bladder. B was confirmed to counteract dose dependently the effect of D on the dog bladder. In the ventricular muscle, the combined electrophysiological effects (D + B) were additive, with no reduction in the effect of D. With the control value set as 100%, the decrease in the maximum rate of depolarization with 5 X 10(-6) g/ml D (90 +/- 6%) was not affected by the same dose of B (D + B: 84 +/- 14%). Moreover, the effective refractory period (ERP) was larger with D + B (128 +/- 12%) than with either B (109 +/- 9%, p less than 0.01) or D (115 +/- 11%, p less than 0.05). In contrast, in the atrial muscle and AV and SA nodes, B had marked acetylcholine-like effects. These were completely suppressed by the addition of D except for the atrial ERP with the highest tested concentration of B (5 X 10(-6) g/ml). In the latter case, the prolongation of ERP was minimal (B + D: 105 +/- 14%) as compared with D alone (130 +/- 15%). Since the plasma concentration of B after oral administration of a clinical dose is expected to be on the order of 10(-7) g/ml, no practical effect is anticipated. We conclude that B can be expected to counteract urination disorders caused by D without reducing D's antiarrhythmic efficacy.

Anesthesia↗
PubMed1989

[Usefulness of exercise Tl-201 myocardial scintigraphy: comparison with positron emission tomography].

To evaluate the usefulness of exercise Tl-201 myocardial scintigraphy, we performed positron emission tomography and conventional exercise Tl-201 emission computed tomography (ECT) in 33 patients with old anterior myocardial infarction (Q-MI: 24, non Q-MI: 9). N-13 ammonia was used as a blood flow tracer, and imaging was performed at rest and after multistage, symptom-limited ergometer exercise. After the administration of F-18 deoxyglucose (FDG) at rest in the fasting state, metabolic imagings were performed to evaluate regional exogenous glucose utilization. Tl-ECT showed fixed defects in 19 of the 33 patients, redistribution of the tracer in nine and no defects in five. All patients having partial or complete redistribution on Tl-ECT showed exercise-induced ischemia on PET with N-13 ammonia and an increased uptake of FDG in the hypoperfused region, suggesting the presence of ischemic but potentially salvageable tissues. In addition, PET with N-13 ammonia detected periinfarct ischemia in nine of the 19 with fixed defects on Tl-ECT, and increased uptakes of FDG were observed in eight of the 19. These results indicate that Tl-ECT may underestimate myocardial viability in clinically infarcted regions. Further studies are needed to determine whether restoring coronary flow improves wall motion in regions with fixed defects on Tl-ECT.

Adult↗
PubMed1989

[A study on amino acid solutions for postoperative parenteral nutrition--evaluation in terms of surgical stress, amino acid composition and its doses].

A newly composed amino acid solution, which contained a 30% branched-chain amino acid (BCAA), and a standard amino acid solution containing 22.6% BCAA were used for total parenteral nutrition following operation of the digestive organs. Their nutritional effects were evaluated by surgical stress (thoracotomy group or non-thoracotomy group) according to the two steps of amino acid doses (1.2g/kg/day administration group or 1.6g/kg/day group). 1. No significant differences could be recognized in an improvement in the serum proteins following administration of BCAA-enriched solution either in the thoracotomy or in the non-thoracotomy group. 2. An improvement in BCAA/AAA molar ratio was seen on the plasma aminogram following administration of BCAA-enriched solution both in the thoracotomy and in the non-thoracotomy groups. 3. No improvement in nitrogen balance following administration of BCAA-enriched solution could be found in the thoracotomy group, while its improving trend was recognized in the non-thoracotomy group treated with 1.6g/kg/day of the amino acid. 4. Neither in the thoracotomy nor in the non-thoracotomy group any significant inhibition of the excreted volumes of urinary 3-methylhistidine could be recognized.

Amino Acids, Branched-Chain↗
PubMed1989

[Clinical trial of 111In-antimyosin antibody imaging: (3) Comparison with 99mTc-pyrophosphate imaging].

Clinical value of 111In-antimyosin monoclonal antibody F ab (AM) was compared with 99mTc-pyrophosphate (PYP) in 13 patients with myocardial infarction and 3 patients with myocarditis. Following PYP injection, PYP imaging was performed 3 hours later. Immediately after PYP imaging, AM was administrated and AM images were obtained 48 hours later. Abnormal accumulation in the infarcted myocardium was observed in 11 patients (85%) on AM images but only in 3 patients (23%) on PYP images. All patients within 8 days after the onset of infarction showed abnormal uptake on both images. Of 5 patients with 1 to 2 weeks after the onset of infarction, abnormal uptake was observed in all of them on AM images but only in one of them on PYP imaging. Furthermore, of 6 patients with more than 2 weeks after the onset, AM imaging showed abnormal uptake in 4 (67%) but PYP imaging did not show abnormal uptake in any of them. Similarly. Of 3 patients with myocarditis, diffuse uptake in the myocardium ws observed in 2 of them on AM images but none of them showed abnormal uptake on PYP images. We conclude that AM imaging is a useful means for identifying not only acute stages but also subacute stages of myocardial necrosis where PYP imaging did not show any abnormality.

Adult↗
PubMed1989

Identification and characterization of an avian reovirus isolated from black-tailed gull (Larus crassirostris).

An isolated virus from the feces of nestlings of Black-tailed gulls living on the Kabu-Island, Hachinohe-city, Aomori-prefecture, was identified as an avian reovirus from its morphological, physicochemical and biological features. Serologically, the isolate has a 62% of relatedness to TS-17 strain, a prototype of avian reovirus in Japan. The isolate showed no significant virulences to one-day-old SPF chickens, and showed low mortalities to chicken embryos, although it formed remarkable lesion onto chorioallantoic membrane.

Animals↗
PubMed1989

High frequency of spontaneous acute myocardial infarction due to small coronary artery disease in dead (NZWxBXSB)F1 male mice.

To determine whether or not male (NZWXBXSB)F1 [WXB)F1) mice exhibiting a lupus-like syndrome died of acute myocardial infarction (MI), and whether acute MI is directly related to small coronary artery disease, acute and old MIs were examined histologically in 55 dead (WXB)F1 male mice and 30 age-matched, surviving (WXB)F1 male mice used as a control group. In each heart from the 15 dead mice with MI and the five surviving mice without MI, 300 to 400 5-microns-thick serial sections were made; every fourth section was stained. Acute MI was found in 35 (64%) dead mice and in one (3%) survivors, whereas old MI was found in 50 (91%) dead mice and 17 (57%) survivors: a significant difference between the dead and surviving mice. The MIs were numerous, scattered, and small in most mice. Quantitative analysis revealed that the percentage of acute MI and old MI in the left ventricular (LV) wall was 6% +/- 11% and 3% +/- 3% in the dead group, and 0.4% and 2% +/- 3% in the control group. This indicated that recurrent acute MI is a major factor in the death of the mice. Although all the epicardial major coronary arteries of the (WXB)F1 male mice were intact, significant stenoses were noted in the intramyocardial small arteries. The serial sections in the 15 dead mice with MI revealed 1) segmental occlusive thrombi in the infarct-related small coronary artery in 14 of the 20 foci of acute anemic MIs, two of the 18 foci of acute hemorrhagic MIs, and four of the 58 foci of old MIs; and 2) segmental intimal thickenings in the infarct-related small artery in six of the 20 foci of acute anemic MIs, two of the 18 foci of acute hemorrhagic MIs, and 56 of the 58 foci of old MIs. There was no evidence of small coronary artery disease in the surviving mice without MI. The thrombus would result in thickened intima as MI progresses from the acute to the old stage. Because it was established that acute MI of hemorrhagic type follows reperfusion after transient occlusion of the coronary artery, hemorrhagic acute MI with rare incidence of thrombi in this mouse suggests that thrombolysis occurs after occlusion due to thrombus formation. Thus, the pathogenesis of multiple MIs is occlusive thrombi, recanalization in small coronary arteries or both. Some of the mice had dilated cardiomyopathy (DCM)-like features (marked LV dilatation).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

[Assessment of myocardial viability by quantitative analysis of stress Tl-SPECT--comparison with FDG-PET].

Stress Tl-201 tomography (SPECT) is widely used for evaluating myocardial viability. To assess its value, redistribution (RD) on SPECT was compared with metabolic imaging using FDG. Thirty patients with coronary artery disease underwent stress-3 hour Tl-201 SPECT and PET using N-13 ammonia and FDG. RD was classified into 4 grading, including complete RD (CR), incomplete RD (IR), persistent defect (PD) and additional minimal RD (MR) defined as no definite RD on visual analysis but faint RD with Bull's eye quantitative analysis (QNT). All but one segment with CR or IR were viable regions (normal or ischemic regions) by PET. Of 74 segments without RD on visual analysis, 31 segments (42%) had RD by QNT (MR). All of them were viable regions by PET. Thus, QNT identified 31 segments (63%) of the metabolically viable segments which the visual Tl-201 analysis did not show RD and classified as myocardial scar. However, even such QNT cannot detect ischemic myocardium in 18 segments (42%) containing metabolic activity on PET. These data indicate that QNT of RD on Tl-201 SPECT is considered as a valuable means for assessing myocardial ischemia.

Aged↗
PubMed1989

[Correlations between results of selective intracoronary thrombolysis and histologic findings of the infarct-related coronary arteries].

To define the histopathogenesis of successful and unsuccessful recanalization following selective intracoronary thrombolysis, coronary angiography (CAG) in thrombolysis and histologic findings were compared in 13 patients who died within four days (mean 1.5 days) after the procedure. Thirteen infarct-related arteries were evaluated in respect to recanalization; presence of an intraluminal thrombus, and rupture and hemorrhage of atheromatous plaques were histologically evaluated in serial sections. Intraluminal thrombi of the infarct-related coronary artery were found in all of the five cases with unsuccessful recanalization and in none of the eight cases with successful recanalization. Rupture and hemorrhage of atheromatous plaques in infarct-related arteries were observed in all of the five cases with unsuccessful recanalization and in seven of the eight cases with successful recanalization. It was concluded that 1) in recanalized cases, thrombi are considered to be lysed; 2) unsuccessful recanalization does not necessarily indicate the absence of thrombi; and 3) rupture and hemorrhage of atheromatous plaques do not affect recanalization.

Aged↗
PubMed1989

[Transesophageal Doppler echocardiography in the diagnosis of dissecting aortic aneurysm].

Transesophageal Doppler echocardiography (TEDE) was performed in three patients with proven or suspected DeBakey type I and type III aortic dissection. Case 1: A 66-year-old woman, with DeBakey type I aortic dissection. Clear images of a widened dissected aorta and an intimal flap were obtained in both the ascending and descending aorta, including the aortic arch. The site of an entry into the false lumen was identified by the defect of the intimal flap and the pulsatile entry flow through it. The reentry into the true lumen was also identified near the orifice of the celiac trunk. In this case, the observation was performed using this technique during the operation; i.e., replacement of the ascending aorta with an artificial graft. Case 2: A 77-year-old man, DeBakey type III aortic dissection. The study was performed after surgery which consisted of replacement of the descending aorta with an artificial graft. TEDE provided clear images of the artificial graft, the aorta, and their boundaries. The remaining intimal flap was clearly confirmed. Case 3: An 80-year-old man, DeBakey type III aortic dissection. In this case, though abdominal echography suggested aortic dissection, angiography and X-ray CT failed to facilitate the diagnosis. Only TEDE confirmed the diagnosis. The abnormal flow via the entry directing toward the false lumen was clearly demonstrated on the color Doppler images. We therefore conclude that TEDE is a useful and reliable means of diagnosing dissecting aortic aneurysm.

Aged↗
PubMed1989

[A double-blind comparative study of intracoronary administration of GE-0943 and urokinase: multicenter study].

Coronary thrombolysis with plasminogen proactivator, GE-0943, was undertaken in patients with acute myocardial infarction and compared with urokinase. Fifty patients were given 6000 units of GE-0943 intracoronary and the totally occluded infarct-related arteries were recanalized in 92.0%. Fifty-four patients who were given 3000 units of GE-0943 intracoronary demonstrated a recanalization rate of 68.2%, while intracoronary administration of urokinase in 54 patients showed a recanalization rate of 70.4%. There was only one patient with hemorrhagic complication among GE-0943 3000-units group, none among GE-0943 6000-units group, and 5 among urokinase group. Thus, intracoronary administration of GE-0943 is very effective and safe with a dose up to 6000 units.

Adult↗
PubMed1989

[Serial assessment of cardiac function during and after exercise by an ambulatory ventricular function monitor (VEST)].

Cardiac function was serially assessed during and after exercise by an ambulatory ventricular function monitor (VEST) in 31 patients who received coronary angiography. Based on the study of fluctuation during the baseline recording, greater than or equal to 6% change in ejection fraction (EF) was considered significant. The serial changes in EF during exercise was divided into 5 types, including continuous increase (type A), initial increase but return to the baseline (type B), no change (type C), initial increase but later decrease below the baseline (type D), and continuous decrease (type E). Among 8 normal subjects, their EF changes during exercise showed type A in 3, type B in 2, type C in 2, and type D in 1. Among 21 patients with coronary artery disease, the EF changes showed type A in 5, type B in 4, type C in 4, type D in 5 and type E in 3. Thus, there was a significant overlap in EF response between normal and coronary patients. However, every patient showing type A and B had single-vessel disease, and 63% of them had persistent thallium defect without redistribution. After the exercise, 29 patients showed rapid increase in EF. The time to the peak EF was significantly longer in coronary patients (1.88 +/- 1.24 min) than that in normal cases (0.88 +/- 0.55 min) (p less than 0.05) particularly in patients with multi-vessel disease (2.22 +/- 1.29 min). In addition, those showing type C, D or E tended to have a longer time to peak EF and more increase in EF after exercise than those showing type A or B. These data suggest that VEST is suitable for continuous measurement of cardiac function during and after exercise which provided valuable indices for assessment of severity of ischemia in coronary artery disease.

Adult↗
PubMed1989

[Clinical trial of 111In-antimyosin antibody imaging: (1). Assessment of tracer kinetics and imaging time].

The human clinical trial of 111In-antimyosin antibody was performed in 20 patients with various cardiac disorders to assess its safety and tracer kinetics and to determine the optimal imaging time. There were no side effects derived from this tracer after its administration. The skin test and the antimurine antibody were both negative in any patient. The radiation dose to the kidney (3.6 rad) and to the whole body (0.36 rad) was acceptable. The half life of the blood clearance was 6.3 hours (fast component) and 25.8 hours (slow component) with the relatively high retention of blood activity at 24 hours (21%) and at 48 hours (11%). The planar images at 24 hours after the tracer administration in 4 patients showed high residual blood-pool activity without delineating significant myocardial uptake, while the images at 48 hours clearly demonstrated the presence or absence of discrete myocardial uptake. However, 2 patients showed significant residual blood-pool activity at 48 hours after the injection which needed 72 hour delayed scan in order to identify the myocardial uptake. In one patient, the single-photon tomography (SPECT) was useful to delineate the myocardial uptake from the residual blood-pool activity at 48 hours after the injection. Although this tracer provides an elegant technique for identifying myocardial necrosis, it needs 48 hours delayed scan and/or SPECT imaging because of relatively slow blood clearance.

Aged↗
PubMed1989

[Clinical trial of 111In-antimyosin antibody imaging: (2). Imaging of myocardial infarction and myocarditis].

A new scintigraphic method to detect myocardial necrosis has been developed using antimyosin monoclonal antibody F ab labeled with indium-111 (111In-antimyosin). We investigated 111In-antimyosin scintigraphy in 35 patients with myocardial infarction, 5 patients with myocarditis and 3 patients with angina pectoris. 111In-antimyosin F ab was administered iv and antimyosin images were recorded by planar and single photon emission computed tomography (SPECT) 48-72 hrs after injection. Planar images showed discrete localization of 111In-antimyosin in 26 of 27 patients within 16 days after the onset of acute myocardial infarction in 14 of whom creatine kinase, glutamic oxaloacetic transaminase and lactic dehydrogenase had already normalized. In addition, positive scans were also obtained in 4 of 8 patients 1 to 9 months after the onset of the disease. Three patients with acute myocarditis (two of whom were biopsy-proven) had positive scans 2 and 4 weeks after the onset of the disease. Although mechanism of persistent positive anti-myosin images in the chronic stage remains to be clarified, 111In-antimyosin scintigraphy holds potential promise as a noninvasive method for the detection of myocardial injury.

Adult↗
PubMed1989

Quantitative analysis of regional wall motion by gated myocardial positron emission tomography: validation and comparison with left ventriculography.

Electrocardiographically gated positron emission tomography (ECG-gated PET) with [13N] ammonia was used to assess regional myocardial wall motion of left ventricle (LV) based on a nongeometric method in nine healthy volunteers and 16 patients with coronary artery disease (CAD). Three transverse sections (upper, middle, and lower) with 16-mm intervals at end-diastole (ED) and end-systole (ES) were analyzed. The LV wall was divided into eight segments with every 30 degrees from septal wall to lateral wall. Based on circumferential profile analysis, the percent count increase [( ES count - ED count) divided ED count x 100) in each segment was analyzed as an index of regional wall motion. In the study of normal controls, the percent count increase was the lowest (32.9 +/- 7.2%) at septal wall of the lower slice and the highest (72.8 +/- 26.5%) at lateral wall of the upper slice (p less than 0.01). In five normal controls, the percent count increase was compared with the percent systolic wall thickening analyzed by magnetic resonance imaging, and a good correlation was observed (r = 0.84). In the study of patients with CAD, the percent count increase was compared with wall motion assessed by left ventriculography (LVG). The percent count increase significantly decreased as wall motion on LVG worsened. In addition, the value in normal controls tended to be higher than that in the segments with normal wall motion in patients with CAD. Thus, quantitative analysis of regional wall thickening was feasible by ECG-gated PET, which should be useful for combined analysis of regional function, perfusion and metabolism in patients with CAD.

Adult↗
PubMed1988

Uptake of acetylated LDL by peritoneal macrophages obtained from normal and Watanabe heritable hyperlipidemic rabbits, an animal model for familial hypercholesterolemia.

Acetylated low-density lipoprotein (acetyl-LDL) stimulated the incorporation of [14C]oleate into cholesteryl [14C]oleate in peritoneal macrophages from both normal and Watanabe heritable hyperlipidemic (WHHL) rabbits. A degradation study showed that macrophages from WHHL rabbits degraded the same amount of 125I-labeled acetyl-LDL as macrophages from normal rabbits. These findings indicate that macrophages of WHHL rabbits have functional acetyl-LDL receptors.

Animals↗